Q&A with Paul Nelles, Vetter Development Service

PharmTech: What are the advantages of using prefilled syringes, rather than vials, as the primary packaging earlier in clinical studies as opposed to waiting until later in the development process?

Nelles: As ‘patient and caregiver’ friendly administration systems are in great demand, being able to offer solutions in this field can give a company a distinct advantage. The benefits of using prefilled syringes earlier in the clinical phase may actually improve trial appeal, making it easier to recruit medical clinics for clinical trials that use prefilled syringes instead of using traditional vials. Another clinical advantage of using syringes includes precision single-unit dosing, which better meets the requirements of today’s more complex compounds. In addition, the use of syringes reduces overfilling, thus saving valuable API compared to vials.

PharmTech:  Are there any disadvantages?

Nelles: Cost and time are strong incentives in the world of drug development. Although these aspects can often be more than compensated when looking at the drug-development cycle in total, these are two of the reasons why drug development is traditionally done in vials. Vials are well known and the initial set-up work is simpler and faster. There are definitely cases in which vial development makes the most sense, one being in dose-ranging studies. Vials may also be preferred if the drug is meeting a crucial unmet medical need, in which all resources will be directed toward launching it as quickly as possible in vial only.

PharmTech: What factors need to be considered when using a prefilled syringe as a primary package in clinical studies?

Nelles: When starting syringe development, interactions between the device and a drug substance are often a challenge, for example due to silicon content. If the company plans on differentiating its product via a syringe to create a competitive advantage, however, the challenges associated with drug and device must be considered and rectified anyway. Therefore, it is best to advance the potential risks and challenges associated with the drug-syringe device earlier in the development process, enabling a smoother and quicker market entry later on, with the advanced primary packaging device right from the start.

PharmTech: What impact does this have on the regulatory approval process?

Nelles: Generally speaking, there is no real difference in regulatory requirements between a syringe and a vial. For regulatory approval, you must first demonstrate drug protection, that is, that there are no leaks or leaching. Second, the bioavailability of the drug must be proven. Finally, you must prove stability, with no adverse effects on the drug. This is necessary due to the nature of the syringe, such as the existence of silicone oil, which could impact the drug. As in vial development, syringes are tested for long-term stability, which is six months or longer under GMP conditions.

About the Author
Melanie Sena is the Community Manager for Pharmaceutical Technology.